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' Nov. 2 192e. 1,605,866

A. STGER COMBIHED Rm-:osim AND SWITCH Filed May 17, 1922 Patented Nov.2, 1926.

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ANTON STC'ER, CF LONG SLILND O'L', YORK, AESGNGR 'IO AMERICAN MOTION:PICTURE MACE-ENE VJBKS, OF LONG ISLAND CTY, YORK, A FIRII COMPOSED OFANTON EMND NISNEEVSKL v GOIVIBINED RHEOSTAT AND SWITCH.

Application led May 17,

The invention relates to resistance changing mechanisn'i` or rheostats,for example of "the type now extensively employed in connec-.tion withthe control of the filament current of vacuum tubes used in radiocommunication. In such rheostats it is especially desirable to aEordmeans for rather line adjustment of the resistance, aswell as to providefor the cutting off entirely of the lamp current at certain times.

The present invention has for its object a rheostat wherein a micrometeradjustment of the resistance is afforded and wherein the current maybeentirely cut off and in such manner, moreover, that upon restoringsame, the exact resistance to which the rheostat was set at the time ofdisestablishment of `tue current will again be cut in when the currentis reestabiishet. A further object of the invention consists in arheostat of simple and rugged construction and which may be manufacturedat comparatively low cost.

The nature of the invention, however, will "-5 best be understood whendescribed in connection with the accompanying drawings, in whichv F ig.1 is a front elevation of the improved rheostat.

Fig. 2 is an end View thereof.

Fig. 3 is a plan view.

Fig. 4. is a vertical section thru the rheostat.

Similar characters of reference designate corresponding parts t-hruoutthe several views.

Referring to the drawings, designates a suitable support or base havingtwo uprights 11 and 12 at its respective ends and within which ismounted for rotation a metallic shaft 13. This shaft is lprovided at oneend with a knob 14 whereby said shaft may be conveniently rotated, andcarries a drum 15 upon the periphery of which is wound a resistance wire16 in the form of a helix of fine pitch. The one end of said coil isembedded in the drum and the other is electrically connected with theshaft 13 (as shown in F ig. 4t) and against one end of which shaft bearsa spring 17 secured to the base and thru which electrical connection maybe made to the rheostat.

1922. Serial No. 561,605.

A rod 2O is alsomounted in the uprights 11 and 12 for oscillationtherein, being provided at one end with a knob 21 to conveniently effectthis oscillation; and its opposi-te end being squared and having bearingthereon a flat spring 22 serving to lock the rod indifferent positionsas well as to connect same electrically to an external.

source of current supply (not shown).

A slider or brush 25 is carried by the rod 20, being in the `nature of atube encircling same and having a spring tongue 26 bearing upon aportion of the surface of the rodl to resiliently hold the sliderthereto. The slider carries also a brush portion having an edge 27 ofthickness substantially equal to the spacing of the wire 16 of the helixand adapted to fit between two successive convolutions thereof andcontacting simultaneously with both.V `It will be apparent that ifvthedrum 15 be rotated, as by turning knob 14, the slider 25 thru engageientof its edge 27 with the convolutions of '1 the wire coil 16 will beadvanced or re tracted accordingly and will thus cut in or iii? outresistance as may be desired. It will be Y noted also that the change ofresistance is continuous, that is to say in minute fractions of a turnand not in complete turns as is the usual practice where a brush movesover the surface of the turns. Thru the engagement of spring 22 with thesquared enc of rod 20, the proper position of engagement of brush 27 andthe heliX 16 will be insured and the brush edgeheld therein againstlateral displacement d'uring rotation of the drum.

Furthermore, if it. be desired to tempo rarily cut off the supply ofcurrent, the same may readily be effect-.ed by turning the rod 2O thruthe knob 21, as this will cause the edge 27 to swing out of engagementwith the particular `pair of convolutions of the resistance wire andthus interrupt the circuit at this point. The relation of the edge 27with respect to the resistance coil, however, is not disturbed thereby;and as soon as the rod 20 is turned back to cause engagement againbetween edge 27 and the coil, the exact amount of resistance to whichthe rheostat had previously been adjusted will be restored so that it isnot necessary to further manipulate the rheostat aft-er the properadjustment for the lamp has once been determined.

I claim 1. A rheostat, comprising a rotatable drum, a helix ofresistance wire wound thereon, a rod parallelto the axis of therotatable drum and oscillatable in a plane. at right angles thereto, amember mounted to slide freely on said rod and having an extension whoseedge is adapted to fit between two successive convolutions the helix ltobe advanced thereby in either direction asv the drumr` iscorrespondinglyrotated andthereby to increaseor decrease the effective resistance ofthe helix, said slidaltly mounted member being movable into and out` ofContact With the helixby correspondingly turningsaid rod, and electricalconnections to the helix and slider.

2. A- rheost-at, comprising a rotatable drum, a helix of resistance wireWound thereon, an oscillatable rodsquared at one end, a knobat theotherv end thereof for oscillating the rod, a flat spring bearingagainst the vsquared end of said rod, and a= member slidably'mounted onthe rodv and having anextension Whose edge is adapted to fit between andContact with two successive convolutions of the helix.

3'. Ai rheostat, comprising av rotatable drum, a helix of resistanceWire Wound thereon, an oscillatable rod squared at one end, a knob atthe other end thereof for oscillating the rod, a flat spring bearingagainst the squared end of. said rod, a member slidably mounted on therod and-having an-extension Whose edgeis adapted to fit between andcontact with two successive convolutions of the helix, and electricalconnections to said helix and .saidlat spring.

4f. A rheostat, comprising a frame, a metallic shaft rotatably mountedtherein and projecting at one end thru the frame, a knob secured to theother end for rotating said shaft', a brushfbearing against theprojecting end of the, shaft for effecting electrical connectionthereto, a drum mounted on the shaft, a helix of resistance wire woundLon the periphery thereof, one rend be-v ingl connected to the. metallicshaft, a rod mounted to cscillate in said frame, one end projectingbeyond: the frame and squared, a knobatuthe other end'for oscillatingsaid rod, aflatspring bearing against the squared end of: the shaftandlthruewhich electrical connect-.ion may be made thereto, and a tubemovabl'y mounted ontherod andhaving a spring.I tongue for. resilientlyvholding same thereto, said tube having also an extension whose edge isadapted to fit between and contactr with two successive; convolutons ofthe helix.

Signed at. Long Island Cityin the county oflQueens and State of'NeWYorkvthis 13th day of May A. D. 1992.

ANTON STGER.

